INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Jobs

Late rising in feeders of ASTM B148 C95500 castings.

Late rising in feeders of ASTM B148 C95500 castings.

(OP)
Castings weight 120 Kg, Pouring Temp - 1187o C.
Melting in Induction medium frequency furnace.
Ceramic filter of 10 ppi was used. Marble grit plunging was used to remove gas for 4 min approximately in a melt of 170 Kg and Mg was used in ladle for degassing.
Furnace sample was good but late rising seen in the feeders resulting in rejection of castings.
Initially my doubt was on temperature, but I observed that I do not face such difficulty in pouring C95200 and C95800 at same temperature although the castings were of less weight (around 90 Kg).
I am practicing CO2 molding process in my foundry. Oil core was used in forming cavity.
Just don't get it why this happens. Any clue?

A M CONTRACTOR

RE: Late rising in feeders of ASTM B148 C95500 castings.

Pictures?

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Late rising in feeders of ASTM B148 C95500 castings.

Why do you suspect late rising in the feeders?
Were the castings below the risers well-filled with no voids?
Any chance the flow path from the main casting volume up to the riser-to-casting intersection was slowed or momentarily stopped up by out-gassing or a bubble of gas? (I'm thinking like a bubble of air in honey or maple syrup rises very slowly past an obstruction, but - once past the obstruction, leaves no trace of its previous passage.)

RE: Late rising in feeders of ASTM B148 C95500 castings.

(OP)
EdStainless Please find attached pics.
racookpe1978 Sir because the furnace sample was good enough to pour. The cavity was filled smoothly and feeders were in action of feeding creating a cone cavity, but within in a few seconds they sparkled and right from the center of the feeder metal started bulging. You can see the attached pics.

A M CONTRACTOR

RE: Late rising in feeders of ASTM B148 C95500 castings.

Moisture or a chemical trapped in the higher levels of sand that began bubbling out - but only once the liquid metal got that high above the casting itself?

RE: Late rising in feeders of ASTM B148 C95500 castings.

(OP)
racookpe1978 - I had a talk with an industrial consultant recently and he has confirmed that this is nothing but mold gas evolving while the metal is yet to freeze completely. I have considered his advice and will take all necessary steps to overcome the defects. I will update here my results soon.

A M CONTRACTOR

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close